Neutrophil-Lymphocyte Ratio as an Independent Predictor of Survival in Pulmonary Arterial Hypertension: An Exploratory Study

Background: The blood neutrophil-to-lymphocyte ratio (NLR) has recently emerged as a powerful predictor of adverse outcomes in some cardiovascular and lung diseases. Pulmonary arterial hypertension (PAH) is a lethal vasculopathy associated with increased inflammation. Although PAH exhibits a higher prevalence among women, men have a poorer prognosis. We investigated the NLR as an independent predictor of transplant-free survival in PAH. Methods: We performed a retrospective analysis of 78 PAH patients from the Quebec PAHBiobank (71% female). We used univariate and multivariate (adjusted for age, sex, renal function, and disease severity) Cox regression analyses to assess the relationship between the NLR and transplant-free survival, in the whole sample, and according to sex. The NLR was categorized as high (≥ 4.8) or low (